1. Technical Field
The present invention relates to metal sandwich sheet structures and, more particularly, to formable metal core sandwich sheet structures and methods and systems for manufacturing same.
2. Description of Related Art
Metal core sandwich structures are known in the art. For example, U.S. Pat. No. 3,525,663 to Hale and U.S. Pat. No. 4,035,536 to Morrison both disclose metal sandwich structures having a formed metal core brazed to two outer metal sheets. However, it is believed that the structures disclosed by Hale and Morrison, and other similar conventional formed metal core sandwich structures, cannot be easily formed into compound curves and other complex shapes without delaminating, wrinkling and/or otherwise losing its structural integrity. Therefore, prior metal core sandwich structures are not well-suited for applications that require formation of compound curves, for example, without delaminating or wrinkling during the forming process.
Other types of metal core sandwich structures, such as honeycomb sandwich structures, are described in U.S. Pat. No. 6,544,623 to Straza, for example. Although this honeycomb core sandwich structure provides improved formability when compared to other metal core sandwich structures, it is relatively expensive to manufacture and, therefore, not well-suited for many commercial, cost-sensitive applications (e.g., automobile bodies).
Therefore, there is a need for an improved metal core sandwich structure that is more economical to manufacture and which exhibits improved formability characteristics without sacrificing structural integrity and strength.